For adjusting a control system, various approaches were conventionally taken such as Kalman filter or neutral network. However, concerning the combustion vibration of a gas turbine, as matters now stand, its phenomenon is complicated, and field shakedown is adjusted based on experience and know-how of an operator now as in the past.
Concerning monitor of combustion vibration during driving, there is a known technique in which data is collected by a pressure sensor disposed in a combustor, an abnormal condition of the combustion vibration is grasped at an early stage by analyzing frequency of the combustion vibration by this data, and the driving state of the combustor is monitored while attaching importance to soundness.
FIG. 19 shows a combustion abnormality monitoring apparatus (gas turbine abnormality monitoring apparatus) disclosed in Japanese Patent Application Laid-open No. 11-324725. This monitoring apparatus uses a pressure sensor 100 disposed in the gas turbine combustor, an A/D converter 101 for converting a detection signal from the pressure sensor 100 into digital data and receiving the same, a frequency analyzer 102 for decomposing the digital data into frequency component and analyzing the same, a judging condition setting section 103 for variably setting reference data concerning a frequency component to be monitored based on an output of a gas turbine combustor and a parameter defined by a fuel supply amount thereof, a judging processing section 104 for extracting a frequency component caused by combustion vibration phenomenon from analysis data of the frequency component based on the reference data, comparing an amplitude value of the frequency component and an amplitude value of data concerning the frequency component to be monitored under normal conditions with each other, thereby judging the combustion vibration state, and a result display section 105 for displaying data concerning the judgement result.
In this monitoring apparatus, frequency of the combustion vibration is analyzed by data from the pressure sensor 100, the amplitude value of vibration at the time under normal conditions is compared with an actually measured value at every frequency, and it is possible to judge whether the combustion vibration is abnormal.
In the conventional monitoring apparatus, however, it is necessary to previously input an amplitude value of the combustion vibration under normal condition for each frequency, and the value under the normal conditions is substantially a management value for alarm, and combustion vibration can not be detected at an early stage.